Medium conveying device

ABSTRACT

A medium conveying device includes a body in which a conveying path is formed, a separator configured to supply a first medium that is arranged on one side among a plurality of media to the conveying path, a conveyor configured to convey the first medium that is being conveyed and that is arranged on the conveying path along the conveying path, and a rib that protrudes from the one side to a conveying path part between the separator and the conveyor in the conveying path.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2021-101311, filed on Jun. 18, 2021, the entire contents of which are incorporated herein by reference.

FIELD

The embodiment discussed herein is related to a medium conveying device.

BACKGROUND

A medium conveying device that conveys a medium along a conveying path with a curve has been known (Japanese Laid-open Patent Publication No. H07-261484, Japanese Laid-open Patent Publication No. H07-157135, and Japanese Laid-open Patent Publication No. 2020-186079).

One medium that is separated from a plurality of media sometimes curves and, when the medium in a state of being curved is conveyed along the conveying path, a failure sometimes occurs. Occurrence of noise that is caused because the curved medium is corrected to be flat is exemplified as the failure.

SUMMARY

According to an aspect of an embodiment, a medium conveying device includes a body in which a conveying path is formed, a separator configured to supply a first medium that is arranged on one side among a plurality of media to the conveying path, a conveyor configured to convey the first medium that is being conveyed and that is arranged on the conveying path along the conveying path, and a rib that protrudes from the one side to a conveying path part between the separator and the conveyor in the conveying path.

The object and advantages of the disclosure will be realized and attained by means of the elements and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating an image reading apparatus that is provided with a medium conveying device of an embodiment;

FIG. 2 is a cross-sectional view illustrating the image reading apparatus;

FIG. 3 is an enlarged cross-sectional view illustrating the image reading apparatus;

FIG. 4 is a perspective view illustrating a feeding conveying path upper guide and a rib;

FIG. 5 is another perspective view illustrating the feeding conveying path upper guide and the rib;

FIG. 6 is a bottom view illustrating a separation unit and the rib;

FIG. 7 is a back view illustrating a first roller pair;

FIG. 8 is a cross-sectional view illustrating a plurality of thin media that are inserted into a feeding entry;

FIG. 9 is a cross-sectional view illustrating a thin medium that is supplied to a conveying path;

FIG. 10 is a schematic view illustrating a medium conveying device of a comparative example;

FIG. 11 is a schematic view illustrating a thin medium that is supplied by a separation unit of the medium conveying device of the comparative example to a feeding conveying path part;

FIG. 12 is a cross-sectional view illustrating a thin medium that is conveyed by the medium conveying device of the comparative example;

FIG. 13 is a back view illustrating a thin medium that makes contact with a first roller pair of the medium conveying device of the comparative example; and

FIG. 14 is a back view illustrating a thin medium that is interposed in the first roller pair of the medium conveying device of the comparative example.

DESCRIPTION OF EMBODIMENTS

Preferred embodiments of a medium conveying apparatus disclosed in the present disclosure will be described below with reference to the accompanying drawings. Note that the following description does not limit the disclosed technique. In the following description, the same components are denoted with the same reference numerals and redundant description will be omitted.

EMBODIMENT

As illustrated in FIG. 1 , the medium conveying device of the embodiment is provided in an image reading apparatus 1. FIG. 1 is a perspective view illustrating the image reading apparatus 1 that is provided with the medium conveying device of the embodiment. The image reading apparatus 1 includes a medium conveying device body 2, a feeding tray 3 and a scan button 5. The medium conveying device body 2 is formed into a shape almost like a box. A thick medium feeding ejection opening 6 is formed at the front of the medium conveying device body 2. The scan button 5 is arranged on an upper side of the medium conveying device body 2. The feeding tray 3 is formed into a shape of a plate. A placement surface 7 is formed in the feeding tray 3. The feeding tray 3 is arranged on a back side of the medium conveying device body 2 such that the placement surface 7 faces up obliquely and the feeding tray 3 is supported by the medium conveying device body 2. The scan button 5 detects whether the scan button 5 is pressed.

FIG. 2 is a cross-sectional view illustrating the image reading apparatus 1. The medium conveying device body 2 is set on a setting surface 8 on which the image reading apparatus 1 is set. A feeding entry 11, a ejection exit 19, and a conveying path 12 are further formed in the medium conveying device body 2. The feeding entry 11 is formed on the back side of the medium conveying device body 2. The feeding entry 11 is connected to the feeding tray 3 and is connected to the placement surface 7. The ejection exit 19 is formed on the upper side of the medium conveying device body 2. The conveying path 12 is formed inside the medium conveying device body 2. The thick medium feeding ejection opening 6, the feeding entry 11, and the ejection exit 19 are connected to the conveying path 12.

The image reading apparatus 1 further includes a separation unit 14, a conveying unit 15 and a reading unit 16. The separation unit 14 is arranged near the feeding entry 11 inside the medium conveying device body 2. The conveying unit 15 includes a first roller pair 17 and a second roller pair 18. The first roller pair 17 is arranged in an area between the separation unit 14 and the thick medium feeding ejection opening 6 inside the medium conveying device body 2. The second roller pair 18 is arranged in an area between the first roller pair 17 and the thick medium feeding ejection opening 6 inside the medium conveying device body 2. The conveying unit 15 conveys a medium that is supplied to the conveying path 12 along the conveying path 12, using the first roller pair 17 and the second roller pair 18.

The reading unit 16 is formed using an image sensor of a CIS (Contact Image Senor) type. The reading unit 16 is arranged in an area between the first roller pair 17 and the second roller pair 18 inside the medium conveying device body 2. The reading unit 16 captures an image of the medium that is conveyed along the conveying path 12.

The conveying path 12 includes a feeding conveying path part 21, a reading conveying path part 22, and a taking-in conveying path part 23. The feeding conveying path part 21 is arranged between the separation unit 14 and the first roller pair 17. The separation unit 14 and the first roller pair 17 are connected via the feeding conveying path part 21. The reading conveying path part 22 is arranged between the first roller pair 17 and the thick medium feeding ejection opening 6 and is along a plane that is parallel to another plane along which the setting surface 8 is. The first roller pair 17 and the second roller pair 18 are connected via the reading conveying path part 22 and the second roller pair 18 and the thick medium feeding ejection opening 6 are connected via the reading conveying path part 22. The reading conveying path part 22 is connected to the feeding conveying path part 21 via the first roller pair 17. The taking-in conveying path part 23 is arranged under the feeding conveying path part 21 and is along the plane along which the reading conveying path part 22 is, that is, the reading conveying path part 22 and the taking-in conveying path part 23 are along the same plane. The taking-in conveying path part 23 is connected to the reading conveying path part 22 via the first roller pair 17.

FIG. 3 is an enlarged cross-sectional view illustrating the image reading apparatus 1. The separation unit 14 includes a pick roller 25 and a brake pad 26. An outer circumferential surface 28 that is along a cylindrical side surface is formed in the pick roller 25. The pick roller 25 is arranged near the feeding entry 11 inside the medium conveying device body 2 and is supported by the medium conveying device body 2 rotatably on a pick roller rotation axis 27. The pick roller rotation axis 27 is parallel to the plane along which the setting surface 8 is, is parallel to the plane along which the placement surface 7 of the feeding tray 3 is, and is parallel to a plane along which the feeding conveying path part 21 is. The brake pad 26 is formed into a shape of a plate. A pick roller opposed surface 29 is formed in the brake pad 26. The brake pad 26 is arranged under the pick roller 25 inside the medium conveying device body 2 such that the pick roller opposed surface 29 is connected to the placement surface 7 of the feeding tray 3 and such that the pick roller opposed surface 29 makes contact with the outer circumferential surface 28 of the pick roller 25. The separation unit 14 separates one medium that is arranged on the upper side among a plurality of media that are inserted into the feeding entry 11 from the thin media and supplies the separated media to the feeding conveying path part 21 of the conveying path 12.

The first roller pair 17 includes a feed roller 31 and a pinch roller 32. The feed roller 31 is arranged under the reading conveying path part 22 and is supported by the medium conveying device body 2 rotatably on a feed roller rotation axis 33. The feed roller rotation axis 33 is parallel to the pick roller rotation axis 27. The pinch roller 32 is arranged above the reading conveying path part 22 and is supported by the reading conveying path part 22 rotatably on a pinch roller rotation axis 34. The pinch roller rotation axis 34 is parallel to the feed roller rotation axis 33.

The image reading apparatus 1 further includes a taking-in conveying path lower guide 41 and a feeding conveying path upper guide 42, a rib 43, and a feeding conveying path lower guide 44. A taking-in conveying path lower guide surface 45 is formed in the taking-in conveying path lower guide 41. The taking-in conveying path lower guide 41 is arranged under the taking-in conveying path part 23 and is arranged such that the taking-in conveying path lower guide surface 45 faces up and the taking-in conveying path lower guide surface 45 is along the taking-in conveying path part 23. The taking-in conveying path lower guide 41 is fixed to the medium conveying device body 2.

A feeding conveying path upper guide surface 46 is formed in the feeding conveying path upper guide 42. The feeding conveying path upper guide 42 is arranged above the feeding conveying path part 21. The feeding conveying path upper guide 42 is arranged such that the feeding conveying path upper guide surface 46 faces down and the feeding conveying path upper guide surface 46 is along the feeding conveying path part 21. The feeding conveying path upper guide 42 is fixed to the medium conveying device body 2.

The rib 43 is arranged such that the rib 43 protrudes from the feeding conveying path upper guide surface 46. Furthermore, the rib 43 crosses the feeding conveying path part 21. The rib 43 is fixed to the feeding conveying path upper guide 42, that is, is fixed to the medium conveying device body 2 via the feeding conveying path upper guide 42. The feeding conveying path lower guide 44 is arranged between the feeding conveying path part 21 and the taking-in conveying path part 23 of the conveying path 12 and is fixed to the medium conveying device body 2.

The feeding conveying path lower guide 44 is arranged between the feeding conveying path part 21 and the taking-in conveying path part 23 and is fixed to the medium conveying device body 2. The feeding conveying path lower guide 44 is not arranged under a juncture part 24 between the rib 43 and the first roller pair 17 in the feeding conveying path part 21. In other words, the feeding conveying path lower guide 44 is formed such that the juncture part 24 and the taking-in conveying path part 23 are not separate.

FIG. 4 is a perspective view illustrating the feeding conveying path upper guide 42 and the rib 43. The rib 43 includes a right rib 47 and a left rib 48. The right rib 47 is formed platy. The left rib 48 is formed platy. The right rib 47 and the left rib 48 are arranged along two parallel planes, respectively, such that a gap 49 is formed between the right rib 47 and the left rib 48. The two parallel planes along which the right rib 47 and the left rib 48 are perpendicular to the pick roller rotation axis 27 and are perpendicular to the plane along which the feeding conveying path upper guide surface 46 is. The right rib 47 and the left rib 48 are integrally joined to the feeding conveying path upper guide 42.

FIG. 5 is another perspective view illustrating the feeding conveying path upper guide 42 and the rib 43. A right sliding surface 51 is formed in the right rib 47. A left sliding surface 52 is formed in the left rib 48. The right rib 47 and the left rib 48 are arranged such that the right sliding surface 51 and the left sliding surface 52 are along one plane and the right rib 47 and the left rib 48 are fixed to the feeding conveying path upper guide 42. A sliding surface plane along which the right sliding surface 51 and the left sliding surface 52 are are parallel to the pick roller rotation axis 27 and intersects with a guide surface plane along which the feeding conveying path upper guide surface 46 is. An angle formed by the sliding surface plane and the guide surface plane is, for example, equal to 20 degrees. A height H of the right rib 47 with respect to the guide surface plane is equal to the height of the left rib 48 with respect to the guide surface plane and is equal to, for example, 1.7 mm.

FIG. 6 is a bottom view illustrating the separation unit 14 and the rib 43. The pick roller 25 is arranged such that the center of the pick roller 25 in a width direction parallel to the pick roller rotation axis 27 intersects with a plane of symmetry 54. The plane of symmetry 54 is perpendicular to the pick roller rotation axis 27 and intersects with the center in the width direction of the conveying path 12. The brake pad 26 is formed in a shape of a rectangular plate. The brake pad 26 is arranged such that the center of the brake pad 26 in the width direction intersects with the plane of symmetry 54. A width W of the pick roller opposed surface 29 in the width direction is equal to the width of the brake pad 26 in the width direction, is shorter than the width of the pick roller 25 in the width direction of the outer circumferential surface 28 and is, for example, 14 mm.

The rib 43 is formed to be symmetrical via the plane of symmetry 54, that is, is formed such that the right rib 47 and the left rib 48 are arranged symmetrically via the plane of symmetry 54. In other words, the distance from the right rib 47 to the plane of symmetry 54 is equal to a distance D from the left rib 48 to the plane of symmetry 54. Furthermore, the distance between the right rib 47 and the left rib 48 is smaller than the width W of the pick roller opposed surface 29. In other words, the distance D is smaller than a value obtained by dividing the width W by 2 and is, for example, equal to 2.7 mm.

FIG. 7 is a back view illustrating the first roller pair 17. The feed roller 31 includes a right feed roller 61 and a left feed roller 62. An outer circumferential surface 63 that is along a cylindrical side surface is formed in the right feed roller 61. As in the right feed roller 61, an outer circumferential surface 64 that along a cylindrical side surface is formed in the left feed roller 62. The left feed roller 62 separates from the right feed roller 61 and a gap is formed between the right feed roller 61 and the left feed roller 62.

The pinch roller 32 includes a right pinch roller 66 and a left pinch roller 67. In the right pinch roller 66, an outer circumferential surface 68 that is along a cylindrical side surface is formed. In the left pinch roller 67, as in the right pinch roller 66, an outer circumferential surface 69 that is along a cylindrical side surface is formed. The left pinch roller 67 separates from the right pinch roller 66 and a gap is formed between the right pinch roller 66 and the left pinch roller 67. Furthermore, the pinch roller 32 is arranged such that the outer circumferential surface 68 of the right pinch roller 66 makes contact with the outer circumferential surface 63 of the right feed roller 61 and the outer circumferential surface 69 of the left pinch roller 67 makes contact with the outer circumferential surface 64 of the left feed roller 62.

Like the first roller pair 17, the second roller pair 18 includes feed rollers and pinch rollers.

Operation of Image Reading Apparatus 1 of Embodiment

To read images of a plurality of thin media with the image reading apparatus 1, a user places the thin media on the feeding tray 3 such that the thin media are opposed to the placement surface 7 and presses the scan button 5. The thin medium is a medium thinner than a predetermined thickness and a copy paper is exemplified as the thin medium. When a plurality of thin media 71 are placed on the feeding tray 3, because the placement surface 7 faces up obliquely, the thin media 71 move toward the feeding entry 11 by the force of gravity and are inserted into the feeding entry 11 as illustrated in FIG. 8 . FIG. 8 is a cross-sectional view illustrating the thin media 71 that are inserted into the feeding entry 11.

After the scan button 5 is pressed, when the thin media 71 are placed on the feeding tray 3, the separation unit 14 causes the pick roller 25 to positively rotate clockwise in FIG. 8 . The pick roller rotates positively and accordingly one thin medium 72 that is arranged on the top among the thin media 71 is supplied to the conveying path 12 as illustrated in FIG. 9 . FIG. 9 is a cross-sectional view illustrating the thin medium 72 that is supplied to the conveying path 12. At that time, a lower surface of the thin medium 72 makes contact with the pick roller opposed surface 29 of the brake pad 26 and the thin medium 72 slides on the pick roller opposed surface 29 and is supplied to the feeding conveying path part 21 of the conveying path 12. Another thin medium different from the thin medium 72 among the thin media 71 makes contact with the brake pad 26, thus is inhibited from being supplied to the feeding conveying path part 21, and remains in the feeding entry 11 while being placed on the feeding tray 3. The pick roller 25 rotates positively and the thin medium 72 is conveyed along the feeding conveying path part 21 with a front edge 73 of the thin medium 72 making contact with the feeding conveying path upper guide surface 46.

When the thin medium 72 makes contact with the outer circumferential surface 28 of the pick roller 25 and is supplied to the feeding conveying path part 21, the thin medium 72 slides on the pick roller opposed surface 29 and accordingly a center part of the thin medium 72 in the width direction curves up in a raised manner. When the thin medium 72 is conveyed along the feeding conveying path part 21, parts of the thin medium 72 on both ends in the width direction make contact with the feeding conveying path upper guide surface 46 and move along the feeding conveying path upper guide surface 46. The thin medium 72 is conveyed along the feeding conveying path part 21 and accordingly makes contact with the right sliding surface 51 and the left sliding surface 52 of the rib 43. When the front edge 73 makes contact with the right sliding surface 51 and the left sliding surface 52 of the rib 43, the thin medium 72 is conveyed along the feeding conveying path part 21 and accordingly the part curving up in the raised manner at the front edge 73 of the thin medium 72 gets into the gap 49. The thin medium 72 is further conveyed along the feeding conveying path part 21 and accordingly the center part of the thin medium 72 is pushed down by the rib 43. The center part of the thin medium 72 curving up in the raised manner is pushed by the rib 43 and accordingly the thin medium 72 is corrected to be flat.

After the scan button 5 is pressed, when the thin media 71 are placed on the feeding tray 3, the conveying unit 15 causes the feed roller 31 of the first roller pair 17 to positively rotate counterclockwise in FIG. 9 . While the feed roller 31 is rotating positively, the outer circumferential surface 68 and the outer circumferential surface 69 of the pinch roller 32 make contact with the outer circumferential surface 63 and the outer circumferential surface 64 of the feed roller 31 and thus the pinch roller 32 positively rotates clockwise in FIG. 9 , following rotation of the feed roller 31.

The pick roller 25 rotates positively and accordingly the front edge 73 of the thin medium 72 is further conveyed along the feeding conveying path part 21, makes contact with the first roller pair 17 and is interposed between the feed roller 31 and the pinch roller 32. When the thin medium 72 is interposed between the feed roller 31 and the pinch roller 32, the pinch roller 32 pushes the thin medium 72 against the feed roller 31. While the thin medium 72 is being pushed against the feed roller 31, the feed roller 31 rotates positively and accordingly the thin medium 72 is conveyed along the reading conveying path part 22. In the image reading apparatus 1, because the thin medium 72 makes contact with the rib 43, the thin medium 72 can be corrected to be flat before the thin medium 72 makes contact with the first roller pair 17. In the image reading apparatus 1, because the thin medium 72 is corrected to be flat, it is possible to reduce noise of correction that occurs when the thin medium 72 is interposed in the first roller pair 17.

The reading unit 16 captures images of both the surfaces of the thin medium 72 that is conveyed along the reading conveying path part 22. The feed roller 31 rotates positively and accordingly the thin medium 72 is further conveyed along the reading conveying path part 22. The thin medium 72 is further conveyed along the reading conveying path part 22 and accordingly the front edge 73 of the thin medium 72 makes contact with the second roller pair 18. By controlling the second roller pair 18, the conveying unit 15 causes the feed roller of the second roller pair 18 to rotate positively like the feed roller 31 of the first roller pair 17. The feed roller of the second roller pair 18 rotates positively and accordingly the thin medium 72 is conveyed along the reading conveying path part 22. After the front edge of the thin medium 72 passes through the second roller pair 18, the conveying unit 15 conveys the thin medium 72 toward the ejection exit 19 and ejects the thin medium 72 from the medium conveying device body 2 via the ejection exit 19. The image reading apparatus 1 repeatedly executes the operation of conveying the thin medium 72 that is separated from the thin media 71, which are placed on the feeding tray 3, along the conveying path 12 and capturing images of the thin medium 72. The number of times such an operation is repeated equals to the number of the thin media 71.

To read images of a thick medium using the image reading apparatus 1, after pressing the scan button 5, a user inserts the thick medium into the thick medium feeding ejection opening 6 such that the front edge of the thick medium is interposed in the second roller pair 18. The thick medium is a medium thicker than a predetermined thickness and a booklet (passport) that is formed by stapling a plurality of single media is exemplified as the thick medium. After the scan button 5 is pressed, when the thick medium is inserted into the thick medium feeding ejection opening 6, the conveying unit 15 controls the second roller pair 18, thereby causing the feed roller of the second roller pair 18 to rotate reversely. The feed roller of the second roller pair 18 rotates reversely and accordingly the thick medium is conveyed toward the taking-in conveying path part 23 along the reading conveying path part 22.

After the scan button 5 is pressed, when the thick medium is inserted into the thick medium feeding ejection opening 6, the conveying unit 15 further controls the first roller pair 17, thereby causing the feed roller 31 to reversely rotate clockwise in FIG. 9 . The thick medium is conveyed along the reading conveying path part 22 toward the taking-in conveying path part 23 and accordingly the front edge of the thick medium makes contact with the first roller pair 17 and is interposed between the feed roller 31 and the pinch roller 32.

When the thick medium is interposed between the feed roller 31 and the pinch roller 32, the pinch roller 32 pushes the thick medium against the feed roller 31. When the thick medium is pushed against the feed roller 31, the feed roller 31 reversely rotates and accordingly the thick medium is conveyed along the taking-in conveying path part 23. When a back end of the thick medium is arranged in an area between the reading unit 16 and the first roller pair 17 of the reading conveying path part 22, the conveying unit 15 stops reverse rotation of the feed roller 31 and stops reverse rotation of the feed roller of the second roller pair 18.

After the reverse rotation of the feed roller 31 stopes, the conveying unit 15 causes the feed roller 31 of the first roller pair 17 to rotate positively and causes the feed roller of the second roller pair 18 to rotate positively. The feed roller 31 rotates positively and accordingly the thick medium is conveyed along the reading conveying path part 22 toward the thick medium feeding ejection opening 6. The reading unit 16 captures images of both surfaces of the thick medium that is conveyed along the reading conveying path part 22 toward the thick medium feeding ejection opening 6. The feed roller 31 rotates positively and accordingly the thick medium is further conveyed along the reading conveying path part 22 toward the thick medium feeding ejection opening 6 and makes contact with the second roller pair 18. After making contact with the second roller pair 18, the thick medium is conveyed by the second roller pair 18 along the reading conveying path part 22 toward the thick medium feeding ejection opening 6 and is ejected from the medium conveying device body 2 via the thick medium feeding ejection opening 6.

In the image reading apparatus 1, the reading conveying path part 22 and the taking-in conveying path part 23 are along the same plane and therefore, when a thick medium is conveyed, it is possible to reduce the degree by which the thick medium curves. In the image reading apparatus 1, furthermore, when the thick medium is formed of a booklet, because the thick medium does not pass through the separation unit 14, it is possible to prevent a failure exemplified by turning from occurring to the thick medium. In the image reading apparatus 1, because the feeding conveying path lower guide 44 is not arranged between the juncture part 24 and the taking-in conveying path part 23, it is possible to prevent the thick medium from making contact with the feeding conveying path lower guide 44. In the image reading apparatus 1, because the thick medium is prevented from making contact with the feeding conveying path lower guide 44, it is possible to appropriately convey the thick medium along the reading conveying path part 22 and the taking-in conveying path part 23.

As illustrated in FIG. 10 , a medium conveying apparatus of a comparative example is obtained by omitting the rib 43 from the image reading apparatus 1 described above and other components are the same as those of the image reading apparatus 1 described above. FIG. 10 is a schematic view illustrating the medium conveying device of the comparative example. Like the separation unit 14 of the image reading apparatus 1 described above and as illustrated in FIG. 11 , the separation unit 14 of the medium conveying device of the comparative example separates one thin medium 75 from the thin media 71 that are placed on the feeding tray 3 and supplies the thin medium 75 to the feeding conveying path part 21 of the conveying path 12. FIG. 11 is a schematic view illustrating the thin medium 75 that is supplied to the feeding conveying path part 21 by the separation unit 14 of the medium conveying device of the comparative example. When the thin medium 75 makes contact with the outer circumferential surface 28 of the pick roller 25 and is supplied to the feeding conveying path part 21, the thin medium 75 slides on the pick roller opposed surface 29 and accordingly a center part of the thin medium 75 in a width direction curves up in a raised manner.

FIG. 12 is a cross-sectional view illustrating the thin medium 75 that is conveyed by the medium conveying device of the comparative example. The thin medium 75 is conveyed along the feeding conveying path part 21 and accordingly a front edge 76 of the thin medium 75 makes contact with the feeding conveying path upper guide surface 46 of the feeding conveying path upper guide 42. The pick roller 25 rotates positively and accordingly the thin medium 75 is conveyed along the feeding conveying path part 21 while making contact with the feeding conveying path upper guide surface 46 with the center part of the thin medium 75 curving up in a raised manner.

As illustrated in FIG. 13 , the thin medium 75 is conveyed along the feeding conveying path part 21 and accordingly the front edge 76 of the thin medium 75 makes contact with the first roller pair 17 of the medium conveying device of the comparative example with the thin medium 75 curving up in a convex manner. FIG. 13 is a back view illustrating the thin medium 75 that making contact with the first roller pair 17 of the medium conveying device of the comparative example. After the thin medium 75 makes contact with the first roller pair 17, the feed roller 31 of the first roller pair 17 rotates positively and accordingly the thin medium 75 is interposed between the feed roller 31 and the pinch roller 32.

As illustrated in FIG. 14 , the thin medium 75 is interposed in the first roller pair 17 and accordingly a curving part 78 that curves in the thin medium 75 further curves. FIG. 14 is a back view illustrating a thin medium 77 that is interposed in the first roller pair 17 of the medium conveying device of the comparative example. In other words, a part 79 that is interposed between the feed roller 31 and the pinch roller 32 in the curving part 78 is corrected to be flat. A center part 80 that is not interposed between the feed roller 31 and the pinch roller 32 in the curving part 78 gets into a space between the right pinch roller 66 and the left pinch roller 67 and further curves. When the thin medium 75 that curves is interposed between the feed roller 31 and the pinch roller 32, the thin medium 75 is curved and corrected to be flat and accordingly a sound of correction that is a crush sound occurs.

In the image reading apparatus 1 described above, the thin medium 72 is corrected to be flat before the thin medium 72 makes contact with the first roller pair 17 and therefore, compared to the medium conveying device of the comparative example, it is possible to reduce such a sound of correction. In the image reading apparatus 1 described above, the sound of correction is reduced and thus, compared with the medium conveying device of the comparative example, it is possible to reduce noise during use.

In the image reading apparatus 1, the higher the level of the rib 43 with respect to the guide surface plane is, the greater the ability to correct the thin medium 72 whose center curves up in a raised manner because of the separation unit 14 into a flat state is. In the image reading apparatus 1, the larger the width of the rib 43 in the width direction is, the greater the ability to correct the thin medium 72 whose center curves up in a raised manner because of the separation unit 14 into a flat state is. In the image reading apparatus 1, furthermore, the shorter the distance between the separation unit 14 and the rib 43 is, the greater the ability to correct the thin medium 72 with its center curving up in a raised manner because of the separation unit 14 into a flat state is. Based on these features, the shape of the rib 43 is designed appropriately such that the thin medium 72 being in a flat state is interposed in the first roller pair 17.

Effect of Medium Conveying Device of Embodiment

The medium conveying device of the embodiment includes the medium conveying device body 2, the separation unit 14, and the rib 43. In the medium conveying device body 2, the conveying path 12 is formed. The separation unit 14 supplies one thin medium 72 that is arranged on the upper side among the thin media 71 to the conveying path 12. The conveying unit 15 conveys the thin medium 72 that is supplied to the conveying path 12 along the conveying path 12. The rib 43 protrudes to the feeding conveying path part 21 between the separation unit 14 and the conveying unit 15 in the conveying path 12 from the upper side.

In the medium conveying device of the embodiment, the rib 43 pushes the part that curves up in a raised manner in the one thin medium 72 that is separated by the separation unit 14, thereby enabling the thin medium 72 to be corrected to be flat. In the medium conveying device of the embodiment, the thin medium 72 that is separated by the separation unit 14 is corrected to be flat, which enables prevention of occurrence of a failure that is caused because the thin medium 72 curves.

The conveying unit 15 of the medium conveying device of the embodiment includes the right pinch roller 66 that makes contact with the thin medium 72 and that rotates on the pinch roller rotation axis 34 and the left pinch roller 67 that makes contact with the thin medium 72 and rotates on the pinch roller rotation axis 34. The right pinch roller 66 and the left pinch roller 67 are separate from each other and a gap is formed between the right pinch roller 66 and the left pinch roller 67.

When the thin medium 75 that curves is interposed in the first roller pair 17, the part curving up in a raised manner in the thin medium 75 gets into the gap between the right pinch roller 66 and the left pinch roller 67. For this reason, when the thin medium 75 that curves is interposed in the first roller pair 17, the part being interposed in the first roller pair 17 in the thin medium 75 is corrected to be flat and the part that gets into the gap between the right pinch roller 66 and the left pinch roller 67 in the thin medium 75 further curves. The thin medium 75 is corrected to be flat and curved and accordingly a sound of correction that is a crash sound is sometimes caused. In the medium conveying device of the embodiment, the thin medium 72 interposed in the first roller pair 17 is corrected to be flat, which makes it possible to prevent occurrence of a sound of correction and reduce noise.

The separation unit 14 of the medium conveying device of the embodiment includes the pick roller 25 and the brake pad 26. The pick roller 25 makes contact with the upper surface of the thin medium 72 and rotates on the pick roller rotation axis 27 such that the thin medium 72 is supplied to the conveying path 12. The brake pad 26 is fixed to the medium conveying device body 2 and makes contact with the lower surface of the thin medium 72 such that another medium different from the thin medium 72 among the thin media 71 is not supplied to the conveying path 12. The width of the rib 43 in the width direction parallel to the pick roller rotation axis 27 is smaller than the width W of the brake pad 26 in the width direction.

When the width of the rib 43 in the width direction is smaller than the width W of the brake pad 26 in the width direction, the separation unit 14 curves the thin medium 72 such that the center part of the thin medium 72 raises to the upper side. In the medium conveying device of the embodiment, because the rib 43 protrudes to the feeding conveying path part 21 from the upper side, the part curved by the separation unit 14 in the thin medium 72 can be corrected to be flat appropriately.

The separation unit 14 of the medium conveying device of the above-described embodiment includes the pick roller 25 and the brake pad 26; however, the separation unit 14 may be replaced with another separation unit that separates one thin medium 72 from the thin media 71 using another mechanism. One obtained by replacing the brake pad 26 with a brake roller is exemplified as such a separation unit. When no medium is interposed between the pick roller 25 and the brake roller, the brake roller rotates positively in association with the pick roller 25. When one thin medium 72 is interposed between the pick roller 25 and the brake roller, the brake roller rotates positively in association with the pick roller 25. When the thin media 71 are interposed between the pick roller 25 and the brake roller, the brake roller rotates reversely. When the brake roller rotates reversely, another thin medium different from the thin medium 72 among the thin media 71 is not supplied to the conveying path 12 and is conveyed toward the feeding tray 3. Even when the thin medium 72 is separated from the thin media 71 by such a separation unit, the thin medium 72 curves because the thin medium 72 is separated by friction. For this reason, even when such a separation unit is provided, in the medium conveying device, the rib 43 pushes the part curving up in a raised manner in the thin medium 72, which enables the thin medium 72 to be corrected to be flat.

The rib 43 of the medium conveying device of the embodiment includes the right rib 47 and the left rib 48 arrayed in the width direction. The gap 49 is formed between the right rib 47 and the left rib 48. In the medium conveying device of the embodiment, because the curving part of the thin medium 72 gets into the gap 49 between the right rib 47 and the left rib 48, it is possible to reduce a conveying load that is applied when the thin medium 72 is conveyed and the thin medium 72 is conveyed appropriately.

In the rib 43 of the medium conveying device of the above-described embodiment, the gap 49 is formed between the right rib 47 and the left rib 48; however, the rib 43 may be formed into a protruding form in which the gap 49 is not formed. Even when the gap 49 is not formed, in the medium conveying device, the rib 43 pushes the part curving up in a raised manner in the thin medium 72 and accordingly the thin medium 72 can be corrected to be flat.

The conveying path 12 of the medium conveying device of the embodiment further includes the taking-in conveying path part 23 that is arranged under the feeding conveying path part 21 and the reading conveying path part 22 that is along the plane along which the taking-in conveying path part 23 is. The conveying unit 15 conveys the thin medium 72 that is inserted from the feeding entry 11 and that is conveyed along the feeding conveying path part 21 to the reading conveying path part 22 from the feeding conveying path part 21. The conveying unit 15 conveys the thick medium that is inserted from the thick medium feeding ejection opening 6 and that is conveyed along the reading conveying path part 22 toward the taking-in conveying path part 23 and conveys the medium that is conveyed along the taking-in conveying path part 23 to the reading conveying path part 22 from the taking-in conveying path part 23. The medium conveying device body 2 is formed such that the juncture part 24 that is arranged between the rib 43 and the conveying unit 15 in the feeding conveying path part 21 is not separate from the taking-in conveying path part 23.

In the medium conveying device of the embodiment, when the thick medium is conveyed such that the thick medium reciprocates between the taking-in conveying path part 23 and the reading conveying path part 22, it is possible to prevent the thick medium from curving. Furthermore, in the medium conveying device of the embodiment, because the juncture part 24 is not separate from the taking-in conveying path part 23, it is possible to appropriately convey the thick medium from the reading conveying path part 22 to the taking-in conveying path part 23. In the medium conveying device of the embodiment, even when a member for correcting the thin medium 72 into a flat state is not arranged between the juncture part 24 and the taking-in conveying path part 23, it is possible correct the thin medium 72 into a flat state by the rib 43. In other words, in the medium conveying device of the embodiment, it is possible to appropriately convey the thick medium from the reading conveying path part 22 to the taking-in conveying path part 23 and interpose the thin medium 72 that is flat in the first roller pair 17.

In the medium conveying device of the above-described embodiment, the taking-in conveying path part 23 is formed; however, the taking-in conveying path part 23 need not necessarily be formed. Even when the taking-in conveying path part 23 is not formed, as in the medium conveying device of the above-described embodiment, it is possible to correct the thin medium 72 separated by the separation unit 14 into a flat state.

The medium conveying device of the above-described embodiment is used in the image reading apparatus 1, and the medium conveying device may be used in another apparatus. A printer that prints characters or diagrams on a medium is exemplified as the apparatus. In the printer, the reading unit 16 of the medium conveying device of the above-described embodiment is replaced with a printing unit that prints characters or diagrams on a medium that is conveyed along the conveying path 12. In this case, like the medium conveying device of the above-described embodiment, the medium conveying device enables the thin medium 72 that is separated by the separation unit 14 to be corrected to be flat.

The medium conveying device disclosed enables one medium that is separated from multiple media to be corrected to be flat.

All examples and conditional language recited herein are intended for pedagogical purposes of aiding the reader in understanding the disclosure and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the disclosure. Although the embodiments of the disclosure have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the disclosure. 

What is claimed is:
 1. A medium conveying device comprising: a body in which a conveying path is formed; a separator configured to supply a first medium that is arranged on one side among a plurality of media to the conveying path; a conveyor configured to convey the first medium that is being conveyed and that is arranged on the conveying path along the conveying path; and a rib that protrudes from the one side to a conveying path part between the separator and the conveyor in the conveying path.
 2. The medium conveying device according to claim 1, wherein the conveyor includes: a first roller that makes contact with the first medium and that is configured to rotate on a roller rotation axis; and a second roller that makes contact with the first medium and that is configured to rotate on the roller rotation axis, wherein a gap is formed between the first roller and the second roller.
 3. The medium conveying device according to claim 1, wherein the separator includes: a pick roller that makes contact with a surface of the first medium on the one side and that is configured to rotate on a pick roller rotation axis such that the first medium is supplied to the conveying path; and a brake pad that is fixed to the body and that makes contact with a surface of the first medium on a side opposite to the one side such that another medium different from the first medium among the media is not supplied to the conveying path, wherein a width of the rib in a width direction parallel to the pick roller rotation axis is smaller than a width of the brake pad in the width direction.
 4. The medium conveying device according to claim 3, wherein the rib includes a first rib and a second rib that are arrayed in the width direction and a gap is formed between the first rib and the second rib.
 5. The medium conveying device according to claim 1, wherein the conveying path further includes: a first conveying path part that is arranged on a side opposite to the one side with respect to the conveying path part; and a second conveying path part that is along a plane that the first conveying path part is along, wherein the conveyor conveys the first medium that is conveyed along the conveying path part to the second conveying path part from the conveying path part, conveys a second medium that is conveyed along the second conveying path part to the first conveying path part from the second conveying path part, and conveys the second medium that is conveyed from the second conveying path part to the first conveying path part from the first conveying path part to the second conveying path part, wherein the body is formed such that a part that is arranged between the rib and the conveyor in the conveying path part is not separate from the first conveying part. 